This invention relates to a process for flavoring a soluble coffee powder.
More particularly, the present invention relates to a process of this type in which a flavored oil is incorporated in soluble coffee powder to obtain a flavor enhanced product similar in flavor to a roasted coffee.
Soluble coffee powder is conventionally produced by freeze-drying or spray-drying after evaporation of a coffee extract obtained by countercurrent percolation of an extraction liquid through cells filled with ground roasted coffee.
One of the major problems of this type of process lies in the fact that the product obtained does not have the flavor of a roasted coffee which is particularly due on the one hand, to the extraction process, and on the other hand, to the steps of evaporation and freeze-drying or spray-drying which inevitably involve significant losses of flavor.
Various solutions have been proposed in which an oil, generally a coffee oil, is enriched with coffee aromas and then sprayed onto the soluble coffee powder or incorporated in a jar filled with soluble coffee powder.
The principal aroma source known and used for this purpose is the aromas released from ground roasted coffee.
Thus, French Patent Application Publication No. 2,336,088, for example, describes a process in which an inert gas circulates through a ground roasted coffee. This inert gas becomes charged with aromas, and a frost is formed by condensation of the carbon dioxide entrained, moisture and aromas. This frost is then contacted with an oil under predetermined temperature and pressure conditions so that the oil recovers part of the aromas present in the frost. The oil obtained may then be incorporated in a soluble coffee powder.
Unfortunately, it has been known for some time that coffee aroma is fairly unstable and becomes even more unstable when the coffee aroma is separated from its natural substrate. Thus, the practical application of the process described above sometimes leads fairly rapidly to the development of aromatic notes remote from the original aroma, the stability of the end product depending, in particular, upon the structure of the soluble coffee powder, as also described in U.S. Pat. No. 3,769,032.
Various attempts have been made to dissolve only a fraction of the aromas present in the frost in the oil. Thus, one process of this type is known from European Pat. No. 215 164, the main disadvantage of this process being that it is difficult to carry out.